靶向 NKG2A 增强人结直肠癌抗肿瘤 CD8 T 细胞应答

Recently, the inhibitory CD94/NKG2A receptor has joined the group of immune checkpoints (ICs) and its expression has been documented in NK cells and CD8 + T lymphocytes in several cancers and some infectious diseases. In colorectal cancer (CRC), we previously reported that NKG2A + tumor-infiltrating lymphocytes (TILs) are predominantly CD8 + T cells and that CD94 overexpression and/or its ligand HLA-E were associated with a poor prognosis.

This study aimed to thoroughly characterize the NKG2A + CD8 + TIL subpopulation and document the impact of NKG2A on anti-tumor responses in CRC.

Our findings highlight new features of this subpopulation: (i) enrichment in colorectal tumors compared to paired normal colonic mucosa, (ii) their character as tissue-resident T cells and their majority terminal exhaustion status, (iii) co-expression of other ICs delineating two subgroups differing mainly in the level of NKG2A expression and the presence of PD-1, (iv) high functional avidity despite reduced proliferative capacity and finally (v) inhibition of anti-tumor reactivity that is overcome by blocking NKG2A.

From a clinical point of view, these results open a promising alternative for immunotherapies based on NKG2A blockade in CRC, which could be performed alone or in combination with other IC inhibitors, adoptive cell transfer or therapeutic vaccination.